Aero-Space Laboratories, Missile Division, North American Aviation Inc.

Map provided courtesy of the USGS Flagstaff Library.
ABOUT THE MAP

This map has been prepared by Aero-Space Laboratories for use by its scientists and engineers engaged in lunar research and in the hope that it may be a useful standard for graphic presentation of lunar astronomical, and selenodetic cross and studies across the country. The map is unique in that it attempts to identify the largest number of surface features consistent with the resolution of detail visible in a topographically constructed orthonormal photograph.

To obtain this quality, we approached Dr. A. E. Whitford of Lick Observatory, who generously made available to us the original plates of the Moore–Chappell series for selection. These photographs cover a period of ten years and were obtained to be the best ever made. From these we selected two opposing lunar phases which were needed for primary position and which were also centrally clear.

There are two ways of mounting lunar photographs on a gnomonic map. One method involves photography of the moon with your naked eye and hand-drawn map, or by using the telescope which inverts the image. Astronomers long ago adopted the convention that north is down and west is to the right; hence the images are printed for viewing with north at the bottom of the page and south toward the top.

In publishing this map, however, we decided to break with this tradition. We are employing standard and planning projections to take advantage of the moon. As the very worst is a compromise for us to visualize the lunar geography in its true relationship to the earth; it is the identity and position of a detail visible in a photograph that we must find. Engineers will forgive us.

You will notice also that east and west are reversed in relation to the north and south orientation. This again is in accordance with convention. The visible face of the moon was long ago oriented to correspond to terrestrial observations of the earth. It is interesting to conjecture that because of the observing convention the first lunar map could only have started to find the sun rising in the west.

You will notice also that east and west are reversed in relation to the north and south poles. This again is on astronomer's convention. The visible face of the moon was long ago labeled to correspond to the opposing face of the earth. It is interesting to conjecture that because of this labeling, the development on the first lunar milk route may be startled to find the sun rising in the west.

Without discounting the contribution of members of the other earth sciences, it is obvious that the two scientific disciplines which have contributed most to our understanding of the geography and topography of the moon are astronomy and geology. In preparing the map we were fortunate in having the assistance of outstanding members of both sciences. Dr. Dinsmore Alter, Director Emeritus of Griffith Observatory, whose observations of Linné, Plato, Alphonsus and other areas laid the ground work for Kozyrev's discovery in 1958 of the gaseous emissions in the central mountainous ridges of Alphonsus, and Dr. Jack Green of Aero-Space Laboratories, who has an equally outstanding interest in determining by terrestrial analogy the nature and origin of the moon's structure.

More than 700 lunar features have been named since the invention of the telescope—far too many to identify on a map without destroying the pictorial usefulness of the photograph. From this number therefore, Dr. Alter and Dr. Green have selected 300 which are selenographically very prominent or which, as in the case of Linné, are likely to be adduced as evidence in the many more hypotheses which are nearing approaching solution. It is regrettable that many features have not yet been officially named since they could make scientific news. Among these are the great irregular ridges on the floor of Mare Serenitatis, Mare Tranquillitatis, Mare Imbrium and elsewhere; the rille on the west side of the flow of Alphonsus; a similar rille to the east of the Straight Wall; the rectangle just east of the Ptolemaeus–Alphonsus boundary; and the oval ring west of Copernicus.

Between maps put out by various publishers there is some disagreement in the spelling of proper names. This map follows the standard established by the International Astronomical Union and published in the publication, Named Lunar Formations. In three instances, Dr. Green and Alter elected to name features which are not listed in Named Lunar Formations; in these cases the names, shown between quotation marks, have the support of very wide usage.

AERO-SPACE LABORATORIES
MISSILE DIVISION
North American Aviation, Inc.